Tables which perform motion in a cartesian coordinate system, x-y tables, are known in the art. They are typically used in robotic cutting systems to produce cuts in a cartesian coordinate system.
In a x-y table system, a workpiece is placed on the x-y table and the table is moved while a fixed cutting head of the robot cuts the workpiece. Typically, the fixed cutting head is located perpendicular to the x-y table and the cutting is performed a plane parallel to the x-y table.
Unfortunately, x-y tables are fixed in space when they are installed in a cutting system. Typically they are installed in a horizontal direction. Thus, workpieces which require cartesian plane cuts on non-horizontal surfaces must use some other mechanism to produce the cuts.
Typically, the other mechanism used for cutting on non-horizontal surfaces, or on large workpieces, is a rotating end effector, such as a cutting or focusing head, attached to a movable robot. A typical cutting head is described in U.S. Pat. No. 4,618,758. The movable robot moves the cutting head around the workpiece and the cutting head creates a curved cut. As is known in the art, it is not possible to create a perfectly straight cut with a rotating cutting head.